This invention relates to foundation units, and more particularly to a wire support member for a foundation unit, the resulting foundation unit including the wire support member, and a unique method of fabricating the foundation unit from the support member.
Foundation units of the type of the present invention are typically composed of coil springs mounted on a wooden frame. The coil springs are reinforced and held in place by a grid wire top bearing structure. Coils are secured to the grid wire top bearing structure by a series of clips, pigtails or the like, or, as described in U.S. Pat. No. 3,953,903, the coil springs may be snapped into a specially formed grid wire top bearing structure. However, foundation units employing conventional coil springs, although being quite satisfactory for many applications, tend not to provide desired support under all load conditions. Also, fabrication of such a foundation unit can be time-consuming and expensive, and shipping of parts or of the assembled foundation unit can also be quite expensive. Therefore, other types of wire elements, such as those illustrated in U.S. Pat. Nos. 4,377,279; 4,770,397 and 5,005,809 have been developed, the elements having a full range of characteristics from no spring whatsoever to coil spring-like characteristics, and also providing for more economical construction and/or shipment of a foundation unit, either assembled or in a knocked-down manner for assembly at a remote location.